The present invention relates to a coolant pump of an internal combustion engine, having a pump casing, in which a pump shaft is rotatably supported by a water pump bearing assembly. An impeller connected in a rotationally fixed manner to the pump shaft is associated with an intake space. During a rotation of the impeller together with the associated blades, a coolant as a working medium is pumped in a fluid or volume flow from the intake space, via a coolant outlet of the coolant pump, into a cooling system of the internal combustion engine.
In the case of liquid-cooled internal combustion engines, the coolant, in particular cooling water, is pumped in a preferably closed circuit through cooling passages in the region of the cylinders and of the cylinder head with the aid of a coolant pump in order to cool the internal combustion engine. The heated medium is then re-cooled in an air/water heat exchanger by a fan and/or by the relative airflow. The coolant pump used to circulate the coolant is normally driven by an accessory drive mounted in front of the crankcase or by a timing drive inserted within the crankcase.
Document DE 100 57 099 C2 discloses a coolant pump which is used to deliver coolant in internal combustion engines and comprises a pump shaft which is rotatably mounted in a pump casing and, at one end, carries an impeller which rotates in a flow or intake space of the pump casing. At the opposite end from the impeller, the pump shaft is driven by a belt pulley, which is connected for conjoint rotation to the shaft and is driven via a belt by a rotating component of the internal combustion engine. To protect the bearing assembly from the coolant and from impurities, a mechanical seal is provided between the bearing assembly of the pump shaft and the pump space supplied with coolant. The cooling systems of contemporary internal combustion engines for vehicles do not contain a filter system or any device or measures for removing impurities from the coolant.